Schema:
Customer_Master_Index (master_customer_id, cmi_details)
CMI_Cross_References (cmi_cross_ref_id, master_customer_id, source_system_code)
Council_Tax (council_tax_id, cmi_cross_ref_id)
Business_Rates (business_rates_id, cmi_cross_ref_id)
Benefits_Overpayments (council_tax_id, cmi_cross_ref_id)
Parking_Fines (council_tax_id, cmi_cross_ref_id)
Rent_Arrears (council_tax_id, cmi_cross_ref_id)
Electoral_Register (electoral_register_id, cmi_cross_ref_id)
Please answer with SQL.